Phones lie about being at 95-100% charged, because it's bad to keep charging them when at 100%, it stops, waits for it to go down over hours, and charges again.

But then people complain it's not charged to 100% even though they left it charging all night, and because it's easier to lie to people than teach them stuff, they lie.

Or you just market your 1000 mAh battery as 950 mAh battery. But, uhhmm, honesty and marketing...

If you can't charge the battery to 1000 mAh, then state so.

Note that Apple doesn't specify battery capacity spec on iPhone.

You can charge it to that, but you don't want to keep it there, will cause the battery to age faster

Phones reporting 100% charge are usually at around 97%:

https://www.androidauthority.com/how-long-phone-charge-30646...

In old Android phones you could even get those additional 3% by unplugging at 100%, seeing the battery immediately go to 97% and then plugging again. My old Galaxy S4 Mini would even report 94% in such cases - I originally found out about this due to this discrepancy.

The iPhone gives you more of a "gas tank" indicator, as in that 1% charge left is actually closer to 10-15%. Same with 100% - hell knows how much it really is.